Not applicable.
Not applicable.
The invention relates to an electronic control device with integrated fittings protection, particularly for power station applications, comprising at least one power switch for driving and supplying an electrical drive for a fitting which is to be controlled, wherein the at least one power switch of said electronic control device is driven by an electronic computer assembly, whereby said power switch and said electronic computer assembly are arranged inside the housing of the control device, and whereby the electronic computer assembly is supplied with parameterization data for driving the electrical drive for the fitting.
The fittings driven according to the invention have a wide variety of uses, particularly in power station installations, for actuating slides, shutoff devices or valves, for example, whose failure can entail considerable damage to associated machines or even endanger the operators or the environment.
Consequently, the operation of such devices and the recording and avoidance of failures in the fittings take on a greatly increased importance. In conventional control devices for such fitting, bimetallic contacts have been used up to now for recording and limiting electrical supply powers which have risen by comparison with the normal operating states. However, since the warming-up of such bimetallic contacts requires particular minimum warm-up times, which may be much too long, however, to prevent damage t the drive units or the driven fittings, this disconnection response frequently entails problems. In addition, even though they provide an optimum control response for many applications, such contacts are subject to wear, which generally has a negative effect on their switching response.
Frequently, simply disconnecting and connecting a drive unit is not sufficient to satisfy all safety-related requirements, and it would be desirable if a differentiated control response could be matched to the particular given requirements.
The invention is based on the object of developing an electronic control device in accordance such that the above disadvantages are avoided and, in particular, a flexible and very-reliable control response is always allowed.
This object is achieved surprisingly simply in a control device of this generic type in that the at least one power switch for controlling the electrical drive for the fitting is driven by an electronic computer assembly which is arranged inside the housing of the control device and which can be supplied with parameterization data for driving the electrical drive for the fitting. This allows a very precise control response depending on the parameterization data which is input, and there is essentially no wear on the control device over time.
Manual parameterization is achieved in an inexpensive control device in that actuation devices mounted on the housing can be used to supply the computer assembly with parameterization data for driving the electrical drive for the fitting.
Using an external control device, such as a personal computer or a bus adapter assembly, an interface device can be used to supply the computer assembly in a particularly advantageous manner with parameterization data for driving the electrical drive for the fitting, and recorded data can be read out and transmitted.
In this case, momentary values of the power, particularly the real power, which is output can be recorded by a power measuring device and can be compared with associated nominal values.
In accordance with the invention, however, the control device can also have a device for recording at least one electrical quantity which is used to determine, for example as a result of calculation by the computer assembly, the power, particularly the real power, which is output to the drive.
By way of example, it is particularly advantageous to record the real power in drive machines with a small load, since, in this case, the current variation is relatively small. In such a case, a change in the load essentially involves a change in the phase angle, and hence evaluating the recorded real power equates with even more effective machine and installation protection than purely observing the motor 5 current or the apparent power.
A memory device which can be used to store the recorded quantity, particularly the power which is output to the drive, as a function of time and/or displacement can document procedures or can temporarily store motion data from the computer assembly. The memory device advantageously also stores nominal characteristic curves for the drive as a function of displacement and/or time.
In a further preferred embodiment, the computer device can be used to calculate torque values for the drive from the recorded power which is output to the drive, and the torque values can be stored in the memory device and can be compared with nominal characteristic curves for the drive as a function of displacement and/or time. In this case, a person skilled in the art is well aware that the torque depends on the power, particularly the real power, which is output to the drive.
In a further preferred embodiment, the memory device stores control data for voltage and/or current profiles which allows the drive to be started up and/or slowed down steadily, in particular smoothly.
A particularly reliable response is additionally achieved in that the computer device can use the data stored in the memory device to record increased torque values, and, if an increased torque is above a predefined threshold value, a startup operation can be triggered, with prior reverse running and renewed startup, in which case reconnection is not permissible after triggering in the event of excessive torque.
If the computer assembly can be used to calculate a speed-dependent braking and acceleration response using the data stored in the memory device, said braking and acceleration response being able, particularly at any speed, both to cause the drive to stop reliably and to cause the drive to be moved into a predefined safety position, safety disconnection can be effected at any time and without taking a lot of time, irrespective of the motion state of the drive for the fitting.
Quite generally, the computer assembly can trigger any desired operating, safety and/or maintenance functions by responding to a comparison including a stored nominal characteristic curve and at least one momentary value of a recorded electrical quantity for the drive. By way of example, this pertains to emergency disconnection of the drive via a load-shedding relay, alarm signaling, or alternatively signaling the occurrence of wear in a tool, which can be recorded by measuring the real power.
To produce a particularly compact design for the control device, the control device can be arranged in a single housing which has, on its underside, cooling devices and mounting devices for mounting the control device.
The control device according to the invention provide, optimum motor and installation or machine protection for many areas associated with processing machines, in conveying/transport engineering and in broad areas of process engineering.